Sigmund beegmann



(No Model.) y I S. BERGMANN.:

'i t' "WH Lit TE EPHONB.\ fh `u fr No. 337,231'. Patented Mar. 2,' 1886.

WITNBSSES: AIBWBNTOR:

NA PETERS, PholtrLlhagrabhor. Wn'lhinghn. |10.

UNTTEn STATES PATENT OrricE.,V

SIGMUND BERGMANN, OF NEW YORK, N. Y.

TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 337,231. dated March 2, 1886.

Application tiled December 4. 1883. Seri-.1l No.113,502.

.T0 @ZZ whom it may concern:

Be it known that I, SIGMUND BERGMANN, of New York city, in the county and State of New York, have invented a certain new and useful Improvement in rlelephones, of which the following is a specification.

The object of my invention is to produce a telephone-transmitter employingmetalliccontact-points or electrodes controlled by the movement of a diaphragm which shall eniciently transmit articulate speech.

In the joint application of Thomas A. Edison and myself, iiled November 13, 1883, (Serial No. 1ll,6i4,) are set forth means for so limiting the movements of the diaphragm,and hence those of the electrodes or contact-points in a telephone of the kind just mentioned, that they can never be moved apart, even by the strongest sound-vibrations, so far that they will not be in Contact at the beginning of the next succeeding vibration, each vibration, therefore,being responded to from the normal or closed condition ofthe circuit. In that application this efl'ect is produced by the use of a diaphragm having behind it a filling of oil or equivalent material, which. retards its movement, to which diaphragm one electrode or contact-point is attached,while the other is held rigidly.

My present invention relates to a different apparatus for accomplishing the same limitation of the movement of the electrodes; and it mainly consists, iirst, in the employment of an elastic diaphragm carrying an electrode,iu connection with another diaphragm carrying the other electrode, the latter diaphragm beingprovided with the liquid body for limiting its movement; and, second. in placing such liquid on both sides of the diaphragm affected by it, whereby the limitation of its movement is more eiiectively attained. l

In carrying out my invention Iplace in a suitable case a suitable elastic diaphragm, which may be of metal or of insulating materialsuch as mica-and to this I attach one of the plati num or equivalent metallic electrodes. The opposing electrode is attached to another diaphragm having a diaphragm placed a short distance on each side of it, and the intervening spaces are filled with oil or other suitable liquid. Instead, however, of a diaphragm ex- (No model.)

tending across the entire space within the frame,the electrode may be attached to a narrow elastic strip,or to a central plate connected by springs with the casing. These devices I 'consider equivalents of the diaphragm. The

electrodes or contact-points are adjusted before working, so as to be in contact with each other. Preferably the sound-waves are projected against the single elastic diaphragm, and the vibrations thereof are communicated to the contact-point attached thereto. The liquid prevents the opposing diaphragm from being pushed back too far, and the inelasticity of said diaphragm prevents the vibrating contact-point from rebounding so far as to produce an excessive separation of the electrodes.

The accompanying drawing is a sectional view of a telephone embodying my invention.

A is a suitable case of insulating material having a mouth-piece7 B. C is an elastic metal diaphragm. D is a similar diaphragm having a diaphragm, E or E', on each side of it, and the spaces thus formed are iilled with oil,F,or other suitable liquid. A contact-point, a, is

Ycarried by the diaphragm C, and a contact` point, b, by the diaphragm D, the same extending through an aperture in diaphragm E to meet point a. Connections are made to the contacts through the diaphragms by wires l and 2. The sound-waves are projected upon the diaphragm C and communicated to the contact-point mand the diaphragm D,with its surrounding liquid,prevents the too great separation ofthe contactpoints, While the necessary movement to produce the current changes is permitted.

NVhat I claim is- 1. In a telephone, the combination of a diaphragrn free to move under sound-vibrations, carrying one contactpoint7 and a diaphragm provided with a liquid bodylimiting its movement, carrying the other contact-point, substautiallyas set forth.

2. In a telephone, the combination, with a diaphragm and an electrode controlled thereby, of a liquid body on each side of said diaphragm, for limiting its movement, substantially as set forth.

3. In a telephone, the combination of three diaphragms and a liquid body on each side of the central diaphragm, for limiting its move- IOO ment, said central diaphragm controlling au carrying another contact-point and having a electrode, substantially as set forth. diaphragm on each side of it, the spaces be- 4. In a telephone, the combination of a diatween the three last-mentioned diaphragms phragm free to move under sound-vibrations being filled with liquid, substantially as set x5 5 and carrying a contactpoint,and a diaphragm forth.

carrying another contact-point and having a. This specification signed and witnessed this liquid body on each side of it, for limiting its 1st day of December, 1883.

movement, substantially as set forth. SIGMUND BERGMANN.

5. In a telephone, the combination of a dia- NVitneSSes: o phragm free to move under soundvibrations H. W. SEELY,

and carrying a contaet-point,and a diaphragm EDWARD H. PYATT. 

